2012—2014年在西北黄土高原半干旱区甘肃定西（104°36′E,35°35′N）进行大田定位试验,以陇春27号小麦为试材,设全膜覆土穴播充分灌溉（FMSI）、全膜覆土穴播（FMS）、露地穴播（CK）3个处理,测定小麦不同生育时期的土壤含水量、生物量、产量、产量构成因子,计算不同生育阶段耗水量、耗水模系数、耗水强度、水分利用效率等指标,揭示全膜覆土穴播春小麦的耗水特征及其对产量和水分利用的影响。结果表明,2013年和2014年FMSI播种—拔节、拔节—抽穗、抽穗—灌浆、灌浆—成熟4个生育阶段耗水量平均为159.5,115.0,47.7,117.7mm,耗水模系数平均为39.7%,21.5%,13.8%,25.0%,年际间差异不显著,可表征半干旱区全膜覆土穴播春小麦的需水规律。FMS处理0—300cm土层的土壤贮水量在播种期、拔节期、灌浆期均高于CK。在播种—拔节期,FMS在2013年和2014年的耗水强度较CK分别增加了20.0%和5.8%,但灌浆期降低了26.4%和14.1%。2012—2014年FMS的地上生物量在全生育期均显著高于CK,其中成熟期分别增加了95.7%,42.8%和108.7%。FMS的株高、穗长、单株重、穗重、小穗数、穗粒数和千粒重均显著高于CK,使得在耗水量无显著增加的条件下,产量增加了35.4%,58.9%,61.9%;WUE提高了44.6%,54.6%,69.0%。因此,全膜覆土穴播可调节不同降水年型的春小麦耗水进程,使得营养生长期的耗水模系数和耗水强度增加,促进了作物源的建成,在灌浆期耗水量降低的条件下提高产量和WUE。

[Objective] Precipitation is inadequate in add and semiarid areas of Northwest Loess Plateau.Especially,the invalid precipitation,which daily rainfall less than 10 mm,accounts for more than 50％ in winter wheat growth period.Consequently,How to use this part of precipitation sufficiently is a key method to increase the rainfall use efficiency and yield stably of winter wheat in this area.[Method] The winter wheat cultivar Zhongliang was selected as test material,a field experiment was conducted from 2011 to 2015 on Northwest Loess Plateau (104°36′ E,35°35′ N).The designed four treatments were (1) micro ridge-furrow with whole field plastic film mulching and bunching seeding (PRF),(2) whole field soil plastic mulching and bunching seeding (PMS),(3) sand mulching and bunching seeding (SM),and (4) bunching seeding without mulching (CK).The seasonal soil water content in 0-200 cm soil profile,aboveground biomass,yield and its components of winter wheat were recorded;the wheat periodical water consumption in 0-200 cm soil profile,and water use efficiency bad been calculated,to understand the effect of PRF on soil water storage,water consumption characteristics,yield and water use efficiency of winter wheat.[Result] The four-year average soil water storage of PRF at sowing and re-green stages was higher than PMS,SM,CK by 24.3,38.8,7.4 mm and 18.2,26.9,67.8 mm,respectively.PRF averagely increased wheat evapotranspiration from heading to filling stage by 36.0 mm than PMS.As compared with SM and CK,it increased by 12.1 mm and 16.7 mm,40.8 mm and 37.6 mm from turning-green to heading and from filling to maturity,respectively.The abovegrotnd biomass of PRF was higher than PMS by 2.2％-15.4％ at seeding,heading,filling and maturing stages,the significant difference was observed at filling stage in 2011-2012,and at seedling and heading stages in 2014-2015.As compared with CK and SM,the aboveground biomass of PRF was significantly higher at the four growth stages.Spike number,grain number and 1000-grain weight were performed as PRF＞PMS＞SM in four experimental years,the significant difference was not observed among the three treatments,but significantly higher than CK.The yield of PRF was the highest among the four treatments,it reached 4 373.6-4 950.0 kg·hm-2,increased by 2.4％-12.7％ than PMS,and a significant difference was observed in 2012-2013 and 2014-2015.It was significantly higher than SM (except for 2012-2013) and CK (increased by 35.8％-43.8％) in four experimental years.The water use efficiency of PRF increased by 0.4％-12.8％ as compared with PMS,a significant difference was observed except for 2013-2014,it was also significantly higher than SM (except for 2014-2015) and CK (significantly increased by 8.1％-42.1％) in four experimental years.[Conclusion] PRF could use small rainfall (daily rainfall amount ＜10 mm) efficiently,increased soil water storage in 0-200 em profile at sowing and turning-green stages,improved wheat evapotranspiration at filling stage,increased spike number,weight and kilo-grain weight,resulted in the increment of grain yield and water use efficiency.Consequently,the micro ridge-furrow with whole field plastic film mulching and bunching seeding is the better cropping patterns for high yield and efficiency of winter wheat in semiarid areas of Northwest Loess Plateau.

The climate of Gansu turned to be overall warming-drying and partly warming-wetting since 1986. In contrast to that of 1960, the average annual temperature had raised by 1.1°C with the average annual precipitation decreased by 28 mm correspondingly, which made the arid region expanded southward by 50 km in 2010. Climate warming increased the growth period effective accumulated temperature of main food grain crops and lengthened the crop growth period. It changed crop maturity, crop disposition, cropping system and generally increased the cultivatable area and planting altitude above the sea level of major crops and expanded northward the multiple cropping system, which further resulted in expansion of autumn grain crop sown area, shrink of summer grain crop sown area, and replacement of strong winter early maturing varieties by weak winter middle late maturing varieties. It benefited the crop yield by increasing the use efficiency of photo-thermal resources. Warming-wetting climate increased the climate productivity of oasis crop while warming-drying weather decreased the climate productivity of rainfed crops, which were mostly determined by the precipitation regimes and water conditions. Any advanced technique that can increase precipitation use ratio and water use efficiency as well as improve and promote soil quality and fertility should be regarded as an effective countermeasure to increase food grain production under climate change in Gsansu. So, selecting and breeding new crop varieties with the characteristics of strong resistance, weak winter, middle-late mature and high water use efficiency, establishing new planting structure and cropping system that suitable to the precipitation and temperature features of changed climate, are the development direction of food grain production in Gansu to cope with the climate change.

采用单因素随机区组设计,以春玉米沈单16号品种为试验材料,全膜双垄沟播(FMRFC)、沙膜二元覆盖沟种(FSMC)、全沙覆盖平作(SMC)和露地平作(CK)为处理,研究旱地玉米覆盖栽培的土壤水热及产量效应.结果表明:各覆盖处理玉米苗期-抽雄期0～ 25cm土层的平均地温均有所提高,对0～100cm土层的土壤水分的消耗增大,且都以FMRFC居首,比CK增温3.1～3.3℃、多耗水9.8％.收获后,各覆盖处理0～ 20cm土层的土壤水分得到了恢复,但20～ 100cm土层的水分没有恢复到播前状态.覆盖处理显著改善了穗粒数、穗粒重和百粒重等经济性状,增加了玉米产量,提高了作物水分利用效率(WUE),优先次序为FMRFC＞ FSMC＞ SMC＞ CK.FMRFC是半干旱区玉米种植优先选择的覆盖方式,但对0～100cm土层土壤水分消耗较多,对年际水分平衡不利,需深化匹配水分高效调控技术的研究.

【Objective】 Under the plateau climate,study on the planting structure can provide reference to improve the yield and quality of plateau summer vegetables in its planting area.【Method】 Based on counties and meteorological data from 1949 to 2000 in Gansu,by using principal component analysis(PCA) and cluster analysis,selecting indexes of heat,water and light for climate division of plateau summer vegetables in Gansu Province,vegetables suitable to each planting area were determined according to the biological characteristics and the demand of ecological conditions of summer vegetables.【Result】 26 counties were divided into 8 planting designs:the arid planting region of heat tolerance vegetables,the suitable vegetables being balsam pear and wax gourd and luffa;the arid planting region of thermophilic and heat tolerance vegetables,the suitable vegetables onion,tomato,pepper,summer squash,bean,melon;the arid planting region of thermophilic vegetables,the suitable vegetables cucumber,pepper,summer squash,bean;the arid planting region of semi-hardy vegetables,the suitable vegetables pea,cabbage,Chinese cabbage,cauliflower;the arid planting region of thermophilic and semi-hardy vegetables,the suitable vegetables onion,tomato,pepper,bean,Chinese cabbage,cabbage,lettuce and carrot;the semi-arid planting region of semi-hardy and hardy vegetables,the suitable vegetables cabbage,west celery,Chinese cabbage,baby cabbage,cauliflower,garlic,spinach,coriander;the semi-humid planting region of semi-hardy vegetables,the suitable vegetables cabbage,Chinese cabbage,cauliflower,welsh onion and carrot;the arid planting region of semi-hardy and hardy vegetables,the suitable vegetables cauliflower,cabbage,Chinese cabbage,lettuce,west celery,carrot and garlic.【Conclusion】 According to the biological characteristic and demand of ecological conditions of plateau summer vegetables suitable planting vegetables in each planting region were determined.

Three cultivars differing in drought resistance were employed to study water use efficiency(WUE) and nitrogen use efficiency(NUE) of spring wheat,and the relationship between NUE and WUE under different water and nitrogen levels.The results showed that cultivars of Heshangtou and Dingxi No.35 had higher WUE than Ningchun No.4,and Dingxi No.35 had the highest NUE.Leaf level NUE of the three cultivars decreased as nitrogen supplement increased,whole plant NUE was negatively correlated with nitrogen levels.No significant relation was found between nitrogen supplement and leaf WUE,but whole plant WUE was significantly positively correlated with nitrogen level.Obviously,the integral effect of soil water and nitrogen had an important influence on NUE of spring wheat,the response of whole plant NUE to water conditions significantly depended on nitrogen levels.Clear physiological trade-off was found between nitrogen and water use efficiency in wheat,i.e.cultivars with high water use efficiency will have low nitrogen use efficiency,and vice versa.

冬小麦新品种陇鉴386是甘肃省农业科学院旱地农业研究所于1995年用抗锈丰产亲本1321作母本,综合农艺性状优良、抗旱、抗寒、抗锈好的陇鉴127作父本,在连续旱作条件下经6年选育而成,原系号959-5-1-2-3。2001～2002年度参加新品系鉴定试验,较对照增产13.4%;2002～2004年度参加新品系比较试验,2004～2006年区域试验结果表明较对照品种增产4.7%;2006～2007年生产试验较对照增产10.72%,证明是高抗丰产优质的更新换代品种,适宜在甘肃陇东旱塬及同类地区种植。

The characteristics and key regulation techniques have been searched for improve the tilling quality of loessial soil through systematic field tests.The results indicates that the nutrients content of loessial soil are quite lower and continuously falling after 1999-2001 because of serious drought and barren,which implies that the tilling quality of loessial soil is under degeneration.Focusing on drought-and barren-control,research results suggested that the integrated techniques of mountain slope land terracing,ridge and furrow tillage with plastic film,straw and straw plus sand mulches are the key drought-resistant cultivation techniques of loessial soil quality improvement,which may increase natural precipitation rainfall harvesting,storing and use efficiency and improve soil moisture condition;key techniques for drought and barren controlling were proposed,which include deeply applying chemical fertilizer in middle autumn,integrated use of organic inorganic fertilizer and green manure,applying well-composted straw to soil,and involving pea and haricot into the crop rotation system.And then the key soil quality improving techniques of Loessial soil was set up through integrating drought-resistant crops with the drought and barren controlling techniques.

Elevated atmospheric CO2 is not only a reaction caused by a series of climate change,but also has a significant impact on plant physiological process and growth.This article analyses the research progress on the leaf stomatal density,stomatal conductance,plant photosynthesis,transpiration and water use efficiency under the condition of high atmospheric CO2 enrichment.It is found out that under such condition stomatal density decreases significantly,and stomatal conductance also decreases significantly(30%).Plant photosynthesis increases by 50%～100% in general.The decreased rate of transpiration may differ on different plant,about 10%～70%.The water use efficiency(WUE) increases,and its increasing rate under adequate nitrogen treatment is more obvious than that under inadequate treatment.And analysis is made of the interrelationship between them.The conclusion can be used as theoretical basis for breeding crop varieties with high water use and water-saving efficiency.

关于氮素对高大气CO2浓度下C3植物光合作用适应现象的调节机理已有较为深入的研究,但对其光合作用适应现象的光合能量转化和分配机制缺乏系统分析。该文以大气CO2浓度和施氮量为处理手段,通过测定小麦（Triticum aestivum）抽穗期叶片的光合作用-胞间CO2浓度响应曲线以及荧光动力学参数来测算光合电子传递速率和分配去向,研究了长期高大气CO2浓度下小麦叶片光合电子传递和分配对施氮量的响应。结果表明,与正常大气CO2浓度处理相比,高大气CO2浓度下小麦叶片较多的激发能以热量的形式耗散,增施氮素可使更多的激发能向光化学反应方向的分配,降低光合能量的热耗散速率;大气CO2浓度升高后小麦叶片光化学淬灭系数无明显变化,高氮叶片的非光化学猝灭降低而低氮叶片明显升高,施氮促进PSII反应中心的开放比例,降低光能的热耗散;高大气CO2浓度下高氮叶片通过PSII反应中心的光合电子传递速率（JF）较高,而且参与光呼吸的非环式电子流速率（J0）显著降低,较正常大气CO2浓度处理的高氮叶片下降了88.40%,光合速率增加46.47%;高大气CO2浓度下小麦叶片JF-J0升高而J0/JF显著下降,光呼吸耗能被抑制,更多的光合电子分配至光合还原过程。因此,大气CO2浓度增高条件下,小麦叶片激发能的热耗散速率增加,但增施氮素后小麦叶片PSII反应中心开放比例提高,光化学速率增加,进入PSII反应中心的电子流速率明显升高,光呼吸作用被抑制,光合电子较多地进入光化学过程,这可能是高氮条件下光合作用适应性下调被缓解的一个原因。

The top-open chamber was used to simulate elevating atmospheric CO2 concerntration,where wheat(Triticum aestivum L.) was grown under different N application levels and atmospheric CO2 concerntration to study the response of wheat photosynthesis and water use efficiency(WUE) to the change of these two factors and the regulation mechnism of nitrogen application.The results showed that the net photosynthetic rate(Pn),intercellular CO2 concentration(Ci),stomatal limitation value(Ls) and WUE were increased,but stomatal conductance(Gs) decreased gradually,while,transpiration rate(Tr) decreased first and then increased with nitrogen levels increasing under high atmospheric CO2 concentration conditions.Compared to ambiment atmosphric CO2 treatments,Pn was decreased significantly in 0 and 0.1 g N/kg(soil) treatments and significantly increased in 0.2 g N/kg treatment with different atmospheric CO2 concerntration,while Gs,Ci and Tr were decreased.Ls and WUE got to the highest in 0.2 g N/kg,and the differences were significant compared to the other treatments.Pn and Ls were significantly increased with nitrogen levels under the condition of different atmospheric CO2 concerntration.but the response of Ci and Tr were inconsistent.So,WUE and Ls was significantly increased under long-term high CO2 concentration.The photosynthetic down-regulation occured in 0 and 0.1 g N/kg,but not under 0.2g N/kg treatment.

The influence of different planting patterns and density on soybean water use efficiency and grain yield were studied through field experiment.The results showed that the yield of the spot sowing with film cover(SSWFC) increased 25.8% and 32.5% than the furrow sowing with film cover(FSNFC) and the strip sowing without film cover(SSNFC) respectively,and water use efficiency of SSWFC increased 11.1% and 14.2% than FSNFC and SSNFC respectively.Under the different planting patterns,the optimum density for SSWFC,FSNFC and SSNFC is 139 000 plants per hm2,229 000 plants per hm2 and 221 000 plants per hm2.

It is the main way to increase rainwater use efficiency that conserve soil moisture by plastic membrane mulching and collect rainwater by field micro-furrow and ridge on dryland. Potato is the main arid and semiarid crop on northwest loess plateau, and the most important problem to develop local potato-industry is increase its rainwater use efficiency. The field experiment used the mulching methods and furrow-ridge planting model as the treatments, the soil moisture and soil water distribution, crop yield were investigated in the whole potato growth stage, and the water consumption, water use efficiency also be calculated in this experiment, to study the effect of different potato planting model on crop yield and water use efficiency on northwest loess plateau. The results shown that, as the dyadic mulching and furrow-ridge cultivating method which furrow covered by crop straw and ridge covered by plastic membrane was used, the field micro-furrow and ridge was constructed to harvest rainwater, the mulching was used to conserve soil moisture, so the soil moisture was higher than total plastic membrane mulching, especially, the soil moisture in 0-100 cm soil profile of dyadic mulching and furrow-ridge was higher than the mono-plastic mulching in the drought-season of summer. Hence, the dyadic mulching and furrow-ridge cultivating method could increased the yield and water use efficiency by 8.39%~58.38% and 8.46%~67.97% contrasted to the control respectively, it is a reasonable method to increase potato yield on arid area of northwest loess plateau.

The simulated rainfall experiment was carried out to research the impacts of conservation tillage on soil and water loss in sloping field of western Loess Plateau.The paper focuses on the effects of soil water content and soil water erosion by conventional tillage of spring wheat/lucerne intercropping.Cheick pea/lucerne intercropping and potato/lucerne intercropping,and no-tillage with stubble retention of spring wheat/lucerne intercropping,cheick pea/lucerne intercropping.The results showed that:(1) No-tillage with stubble can increase the plant cover on the land and store precipitation on crop yield.In the end of the simulated rainfall experiment,average soil water content by different methods showed that: NTSplNTSclNTSwl TplTclTwl.(2)The runoff process of different methods may be divided into runoff producing,maximum runoff,stability of runoff and disappearance of runoff;soil erosion may be divided into erosion producing,maximum of erosion amount and curtailment erosion.(3) The order of total amounts of runoff and soil loss by six treatments were TwlNTSwlTclNTSclTclNTSpl,and the best model of soil and water conservation is potato/lucerne intercropping.No-tillage with stubble retention of potato/lucerne intercropping is suitable for popularized plant on western Loess Plateau,and it can come into being better ecological benefit,economic benefit and social benefit.

采用裂区试验设计,以施钾水平为主处理,补水时期为副处理,研究了补充供水和钾素处理对马铃薯产量的影响.结果表明:补水和施钾有效改善了土壤水肥条件,使马铃薯植株健壮、茎杆坚实、叶片较厚,增强光合作用能力,从而促使马铃薯块茎增产优质.在陇中半干旱区.旱作马铃薯最佳补水时期是苗期(补水量为90m~3/hm~2).氯化钾施用量为150kg/hm~2,马铃薯鲜薯产量最高为36324.97kg/hm~2,经济最佳投入量为127.48 kg/hm~2,对应的马铃薯鲜薯产量为35178.71kg/hm~2.在马铃薯生育前期土壤严重缺水,降水较少的情况下,苗期补水可改善土壤水分从而增加钾肥的生物有效性,增加钾肥的扩散,有利于马铃薯根系对钾营养的吸收,钾肥的利用效率较高,最高值为37.92kg/kg,而过量施用钾肥其利用率下降.

A comparative experiment of seven different planting patterns on potato was conducted in semi-arid area of central Gansu. The soil temperature, soil water, productivity were examined in this study.The result showed that the treatment of high ridge covered by plastic film and ditch covered by grass was the best pattern, it increased soil temperature and commodity rate of the potatoes. Under the pattern, average soil temperature at the time of 8:00,14:00,20:00 were 19.77 ℃,29.22 ℃,26.94 ℃ and increased by 2.17 ℃,3.34 ℃ and 3.18 ℃ compared with the traditional cultivate pattern respectively; and the treatment also got the highest potato productivity and water use efficiency, they were 24 279 kg·hm~(-2) and 67.61 kg· hm~(-2)·mm~(-1)), enhanced by 58.42 % and 46.03 % respectively compared with the traditional cultivate pattern.

The research aimed to confirm the suitable planting density and sowing date of asparagus lettuce(Taiyuansun) in Hexi corridor high-altitude cold areas.Four planting densities and five sowing dates were designed to study the effects of different planting density and sowing date on the yield and the economic traits of Taiyuansun.The results indicated that plant height,stem diameter,stem length and weight per plant showed a rising trend along with the increasing of planting density.The millet planted at 5 445 plant/667m2 got highest yield.The growth stage was shorten,the yield was decreased,but early bolting rate was increased with the delaying of sowing date of asparagus lettuce.The suitable sowing date of asparagus lettuce was from late April to early May in Hexi corridor high-altitude cold region,and its suitable planting density was 5 445 plant /667m2 in the field with middle fertility.

Jingdian irrigation region is located in the churchyard of Jingtai and Gulang in Northern Gansu.On the basis of studying the present status of agriculture resources in the irrigation region,this paper analyzes the major problems existing in the oasis ecological agriculture sustainable development,raises several measures as taking water-saving irrigation as key stone,optimizing crop plantation structure of the irrigation region,vigorously developing leading industry,strengthening comprehensive management of ecological environment,etc.to ensure the oasis ecological agriculture sustainable development.

A solution cultured simulating experiment had been conducted to study the effects of nitrogen application on the root and shoot growth and water use efficiency of two different drought-resistance spring wheat.The results showed that nitrogen application could increase leaf photosynthetic rate(Pn),transpiration rate(Tr),stoma conductance(Gs),water use efficiency(WUE),and promote the shoot and root growth,but the ratio of root to shoot(R/S) decreased as the nitrogen level increased significantly.Root volume,root bulk density and root water content increased firstly and decreased finally as the nitrogen level increased.It was indicated that the root water content was highest when Root/shoot ratio was about 0.3 in this experimental,but the higher or lower R/S was not favor to the WUE increasing.the Pn,Tr and Gs was increased with the root water content increasing,but the increscent extent of Pn was higher than Tr,so the leaf WUE increased continuously as the root water content increased.Under the rate nitrogen application,the R/S,root volume and root dry matter of dryland cultivar was higher than waterland cultivar,and reasonable nitrogen application can promote root development and harmonize the root and shoot growth,therefore,the drought-resistance capability and higher WUE in wheat plants could be obtained synchronously.

The experiment of split-plot design with potassium application as main treatments and water supplement in different stages as sub treatments was conducted to study the effect of the treatments on potato yield and WUE in semiarid area.The results showed that the difference of the amount of potassium application,different stage of water supplement and their interaction on yield and WUE was in significant level or very significant level.On the condition of K(150 kg/hm2) and seedling of water supplement the yield and WUE reached 36 324.97 kg/hm2,94.2 kg/(mm·hm2),respectively.The yield and WUE increased by 32.24% and 30.7% compared with CK,respectively.